Change Details

**Steps to reproduce**: * Create a template with a parameter and inline format e.g. `{{_|_=_}}` * Using source code editing, include the template on a page and add an empty line with following text to the parameter * Using the VE template dialog, edit the template transclusion and change some of the text in the parameter * Apply the changes and save the page **What happens?** * The newline will be removed creating a dirty diff and possibly weird consequences for the transclusion --- See the original issue where this lead to a broken page while using https://de.wikipedia.org/wiki/Vorlage:Mehrspaltige_Liste > https://de.wikipedia.org/w/index.php?title=Pegah_Ferydoni&diff=220481946&oldid=220458416

While users are not often confronted with this, it's not uncommon that //some// whitespace in template transclusions is relevant. For example, templates often don't accept e.g. `{{example |content=* List}}` or `{{example |content= == Heading ==}}` but must be called like this: ```lang=html {{example |content = == Heading == }} ``` It appears like #Parsoid strips this critical newline character together with all other, non-critical whitespace. While #VisualEditor tries to avoid dirty diffs, there is nothing it can do when an intentional edit is made to such a field. From VE's perspective there was never a newline. **Steps to reproduce**: * Create a template with 2 parameters and the format `inline` (which corresponds to `{{_|_=_}}`) * Using source code editing, include the template on a page, add a parameter and make the parameter's value start with an empty line followed by some text * Using the VE template dialog, edit the template transclusion and change some of the text in this or the other parameter * Apply the changes and save the page **What happens?** * The newline will be removed creating a dirty diff and possibly weird consequences for the transclusion Example dirty diff that broke the page: https://de.wikipedia.org/wiki/Special:Diff/220481946. The template in this example is https://de.wikipedia.org/wiki/Template:Mehrspaltige_Liste.

While users are not often confronted with this, it's not uncommon that //some// whitespace in template transclusions is relevant. For example, templates often don't accept e.g. `{{example |content=* List}}` or `{{example |content= == Heading ==}}` but must be called like this: ```lang=html {{example |content = == Heading == }} ``` It appears like #Parsoid strips this critical newline character together with all other, non-critical whitespace. While #VisualEditor tries to avoid dirty diffs, there is nothing it can do when an intentional edit is made to such a field. From VE's perspective there was never a newline. **Steps to reproduce**: * Create a template with a2 parameters and the format `inline format e.g.` (which corresponds to `{{_|_=_}}`) * Using source code editing, include the template on a page and add an empty line, add a parameter and make the parameter's value start with following text to the parameteran empty line followed by some text * Using the VE template dialog, edit the template transclusion and change some of the text in thethis or the other parameter * Apply the changes and save the page **What happens?** * The newline will be removed creating a dirty diff and possibly weird consequences for the transclusion --- See the original issue where this lead to aExample dirty diff that broken page while usinge the page: https://de.wikipedia.org/wiki/Vorlage:Mehrspaltige_Liste >Special:Diff/220481946. The template in this example is https://de.wikipedia.org/w/index.php?title=Pegah_Ferydoni&diff=220481946&oldid=220458416 iki/Template:Mehrspaltige_Liste.